Rotary device for removing ophthalmic lens

ABSTRACT

A system and method for reducing and removing and ophthalmic lens of a mammalian eye. The system includes a rotary lens-reducing probe device of either straight or curved configuration, said probe device comprising a tubular outer sheath through which a rotatable drive shaft extends. A rotating lens-reducing head member is positioned on the distal end of the drive shaft. The head member is configured and constructed to draw a flow of fluid and lens matter into contact therewith, thereby facilitating complete reduction of the entire lens without requiring significant axial (i.e., longitudinal) movement of the probe within the lens capsule. The distal portion of the tubular sheath is preferably configured to shield a portion of the lens-reducing head, during operation, to avoid inadvertent damage to lens capsule. Also, the distal portion of the sheath may be aimed or positioned to direct the flow of fluid and lens matter created by the rotating head in a preferred flow path within the lens capsule. The device may incorporate means for infusing and/or withdrawing fluid and/or debris into/from the eye.

RELATED APPLICATIONS

This patent application is a continuation-in-part of Ser. No.07/984,229, now U.S. Pat. No. 5,437,678, entitled OPHTHALMIC LENSREMOVAL APPARATUS AND METHOD, filed Nov. 30, 1992.

FIELD OF THE INVENTION

This invention relates generally to apparatus and methods for removingophthalmic lenses and more specifically for removing a cataractousophthalmic lens for vision restoration.

DISCUSSION OF THE PRIOR ART

The lens of a human eye is a crystalline, transparent biconvexintraocular tissue that helps bring rays of light to focus on theretina. The lens is enclosed in a lens capsule and consists of lenscortex, and lens nucleus. The lens capsule is an elastic bag envelopingthe lens and is suspended by fine ligaments (zonule) attached to theciliary muscles. These muscles radially stretch and relax the capsulethereby varying the optical characteristics of the enclosed lens toprovide the desired focus for an image. This is commonly referred to asaccommodation,

The lens cortex is a jelly-like portion of the lens and is locatedbetween the denser inner nucleus and the elastic outer capsule. The lensnucleus is an optically defined-zone which is denser in the centralposition of the lens. This nucleus becomes even denser with age, and caneventually harden and fill increasing portions of the total lens space.Additionally the lens may become opacified.

This opacity and cloudiness of the lens commonly referred to as acataract, may be congenital or may be caused by trauma, disease, or age.The cataractous lens obstructs the passage of light and tends to preventthe formation of a clear image on the retina.

Surgery currently is the only method of restoring vision in a patientblinded by cataracts. The surgical removal of the opacified lens becomesnecessary when visual loss due to a cataract becomes significant. Thelost optical power is typically restored by implantation of anartificial intraocular lens.

The cataract has become one of the most significant and common causes ofocular disability and blindness in our aging population. Cataractprocedures are currently the most frequent surgery performed for aperson over the age of 65. There were 4 million (U.S.: 1.6 million;foreign: 2.4 million) cataract surgeries performed in 1991, a numberwhich is growing at an annual rate of 5%.

The classic method of cataract surgery is the removal of the intact lensthrough a 7-10 mm incision and its replacement with an intraocular lensmade from biocompatible polymers. This extracapsular cataract procedurerestores vision but often causes post-operative complications resultingfrom the large incision, which include a prolonged healing process,increased trauma, and astigmatism. Nevertheless, about half of thecurrent cataract procedures in the U.S. are performed using thisextracapsular technique for removal of the intact lens.

More recently phacoemulsification devices, relying upon ultrasound, havebeen used for emulsifying the lens and removing it through a 3-5 mmincision in a shorter operative time. This technique provides easierrehabilitation and eliminates most of the post-operative complicationsresulting from the larger incision of conventional extracapsularcataract procedures.

For the phacoemulsification procedure, a 3-5 mm limbal or cornealincision is made allowing insertion of the instrument's tip into theanterior chamber in a direction almost parallel to the iris. Once theincision has been made, the central part of the anterior lens capsulemust be widely opened to facilitate emulsification of the lens nucleusand cortical clean-up, as well as to provide for an ideal intraocularlens placement in the sulcus of the posterior chamber.

Phacoemulsification can be performed in the anterior chamber orposterior chamber of the eye. In the case of anterior chamberphacoemulsification, the cataract lens is maneuvered into the anteriorchamber where it is carved and removed from the chamber. Anteriorchamber phacoemulsification is more traumatic to the endothelial layerof the cornea than posterior chamber phacoemulsification, but it isoften an easier procedure for the surgeon to perform. Posterior chamberphacoemulsification consists of carving or shaving the central part ofthe lens while the lens is still in the lens capsule. This method ismore difficult to perform due to the possibility of rupturing theposterior lens capsule and exposing the vitreous humor which fills thevolume of the inner eyeball.

When compared to conventional extracapsular cataract removal procedures,the phacoemulsification technique provides the advantages of a smallerincision, a stronger post-operative globe which reduces astigmatism,better wound closure, lower trauma and quicker improvement in vision.However, the phacoemulsification procedure is contraindicated inpatients having a dislocated cataract lens, a shallow anterior chamber,miotic pupils, low cornea-endothelial cell counts, or myope (a totallyhard lens). The phacoemulsification technique also requires intensetraining in maneuvering the ultrasonic probe to carve the cataract lensnucleus. The stray ultrasound energy can be destructive to theendothelial cells of the cornea ultimately resulting in completedegeneration. Due to these adverse circumstances, only about half of theU.S. surgeons currently prefer to use this phacoemulsification methodover the conventional extracapsular method for cataract removal.

Use of phacoemulsification devices to perform endocapsular cataractremoval has also been investigated. In such a procedure, the cataractouslens must be carved away while both the anterior and posterior sides ofthe lens capsule are left intact. The extreme difficulty associated withthis procedure has limited its adoption so that only about 1% of theU.S. cataract removal procedures are performed using this endocapsulartechnique.

In addition to the above-described phacoemulsification devices, theprior art has included the motor driven cutting instrument, for reducingand removing a cataract-affected lens, as described in U.S. Pat. No.4,368,734 (Banko) entitled SURGICAL INSTRUMENT issued Jan. 18, 1983. Theinstrument described in U.S. Pat. No. 4,368,734 is purportedlyinsertable into the lens capsule and usable to crush and sever thecataract-affected lens. The surgical instrument described in U.S. Pat.No. 4,368,734 includes a gripping implement (e.g., a hook) which islocated opposite the cutting element of the instrument for purposes ofgripping the material or object (e.g., ophthalmic lens) to be removed.Suction and irrigation lumens are incorporated into the instrument forremoving the reduced lens material from the interior of the lenscapsule.

Currently, there remains a need for the development of new ophthalmiclens removal apparatus capable of accomplishing endocapsular lensremoval in a manner which is less time consuming, less skill intensiveand associated with a minimal risk of iatrogenic damage to the posteriorlens capsule.

SUMMARY OF THE INVENTION

The present invention comprises improvements and modifications to therotary ophthalmic lens removal device described in parent applicationSer. No. 07/984,229, of which this application is acontinuation-in-part.

In general, the device described in parent application Ser. No.07/984,229 now U.S. Pat. No. 5,437,678 is a rotary lens-reducing devicecomprising a handpiece having an elongate probe extending distally fromthe handpiece. An elongate rotatable drive shaft passes longitudinallythrough the probe and terminates, at its distal end, in a lens-reducinghead. A protective tubular sheath is disposed about the rotatable shaft.The rotatable shaft and/or the sheath are axially movable so as to allowthe lens-reducing head to be alternately deployed in a) a firstnon-operative position wherein the lens-reducing head is fully locatedwithin the inner bore of the tubular sheath so as to be shielded duringinsertion and retraction of the instrument or b) a second operativeposition wherein the lens-reducing head is advanced out of the distalend of the sheath so as to contact and reduce lens material. Thelens-reducing head is specifically configured such that rotation of thehead will create and sustain a forced circulation of fluid within thelens capsule. Such forced circulation within the lens capsule causes theophthalmic lens to be pulled or drawn into contact with the rotatinglens-reducing head, without the need for significant axial movement ormanipulation of the probe while the lens-reducing head is rotating. Theability of the device to accomplish complete reduction of the ophthalmiclens, without requiring significant axial movement or manipulation ofthe probe concurrently with rotation of the lens-reducing head, servesto minimize the chance of iatrogenic perforation of the posterior lenscapsule during the procedure.

Also, the preferred device described in parent application Ser. No.07/984,229 now U.S. Pat. No. 5,437,678 incorporates a single passagewaywhich extends longitudinally through the probe, and which may bealternately used for infusion of irrigation fluid into the lens capsuleand aspiration of fluid/debris from the lens capsule.

The modifications and improvements which distinguish the presentinvention over that which was specifically described in parentapplication Ser. No. 07/984,229 now U.S. Pat. No. 5,437,678 include thefollowing:

The provision of a modified protective tubular sheath having a distalend which is tapered, beveled or of otherwise non-symmetricalconfiguration such that a portion of the sheath continues to cover orshield a portion (e.g., one side) of the lens-reducing head, even whilethe lens-reducing head is located in its "operative" position. By sucharrangement, the non-symmetric distal tip of the protective sheathserves to shield a portion (e.g., one side) of the rotatinglens-reducing head during use, thereby preventing the lens-reducing headfrom inadvertently perforating the portions of the lens capsule whichare located adjacent the protected portion (e.g., one side) of thelens-reducing head. Additionally such non-symmetric configuration of thedistal tip of the protective sheath can function to direct the flow offluid which is discharged from the rotating lens-reducing head in adirection away from the adjacent wall of the lens capsule therebyminimizing the severity or force with which the fluid impinges againstthe lens capsule. Furthermore such asymmetric configuration of thedistal tip of the sheath can provide a sealing surface which contactsthe surrounding puncture opening or incision in the lens capsule,thereby facilitating operation of the instrument with only minimalinsertion of the sheath into the lens capsule, the opening in the lenscapsule being of a generally oblong shape due to the angled insertion ofthe instrument. Also, the configuration of the distal portion of thesheath is preferably capable of skewing or deflecting the forcedcirculation of fluid which is created by rotation of the lens-reducinghead. Such skewing or deflection of the flow enhances the ability of thedevice to set up a desired forced circulation of fluid around theperiphery of the lens capsule, when the probe is maintained in apreferred position therewithin. Such directing or channeling of theforced circulation around the outer periphery of the fluid within thelens capsule facilitates rapid and complete reduction of the entirelens, without any significant requisite movement or manipulation of theprobe. Furthermore, such directing or channeling of the forcedcirculation around the outer periphery of the lens capsule may optimizethe efficiency of the lens-reduction procedure because such peripheralflow path is consistent with the anatomical configuration of the lenscapsule, and the fact that the lens itself is usually made up ofrelatively hard material in its center with softer material around theperiphery thereof.

The provision of separate fluid infusion and fluid/debris aspirationpathways extending longitudinally through the probe, such thatirrigation fluid may be infused into the lens capsule concurrently withthe aspiration of fluid/debris therefrom, or at least without therequired interruption of one such procedure to permit accomplishment ofthe other, as is required with the single infusion/aspiration pathwayincorporated in the preferred device described in parent applicationSer. No. 07/984,229now U.S. Pat. No. 5,437,678.

The provision of a specific embodiment of the invention wherein theprobe portion of the instrument is of a curved configuration, ratherthan a straight configuration.

Further objects and advantages of the present invention, as well as thespecific manner in which the modifications and improvements of thepresent invention interact with the basic elements of the device asdescribed in parent application Ser. No. 07/984,229, now U.S. Pat. No.5,437,678 will become apparent upon reading and understanding of thefollowing detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic showing of a rotary ophthalmic lens removal systemof the present invention along with a longitudinal sectional view of ahuman eye.

FIG. 2 is an enlarged perspective view of the distal end of the probeportion of the ophthalmic lens removal device shown in FIG. 1.

FIG. 3 is a perspective view of the device of FIG. 1 positioned forinsertion into the eye of a human being.

FIG. 4 is a longitudinal sectional view of a portion of the rotaryophthalmic lens removal device of the present invention.

FIG. 4a is an enlarged longitudinal sectional view of the distal end ofthe probe portion of the device of FIG. 4 wherein the protective sheathpositioned in its "operative" position relative to the rotatablelens-reducing head of the device.

FIG. 4b is an enlarged longitudinal sectional view of the distal end ofthe probe portion of the device of FIG. 4 wherein the protective sheathis positioned in its protective or first "non-operative" positionrelative to the rotatable lens-reducing head of the device.

FIG. 4c is an enlarged longitudinal sectional view of the distal end ofa modified embodiment of the probe shown in FIG. 4.

FIG. 4d is an enlarged perspective view of the rotary lens-reducing headof the device shown in FIG. 4.

FIG. 5a is an enlarged elevational view of an alternative distal tipconfiguration for the probe portion of the device of FIG. 4.

FIG. 5b is an enlarged elevational/cut-away view of an alternativedistal tip configuration for the probe portion of the device of FIG. 4.

FIG. 5c is an enlarged bottom view of an alternative distal tipconfiguration for the probe portion of the device of FIG. 4.

FIG. 6a is a longitudinal sectional view of a human eye into which theprobe portion of a rotary ophthalmic lens removal device of the presentinvention has been inserted.

FIG. 6b is a frontal view of a human eye wherein a rotary ophthalmiclens removal device of the present invention has been inserted.

FIG. 7a is an elevational view of the distal end of the probe portion ofthe preferred embodiment of the ophthalmic lens removal device describedin parent application Ser. No. 07/984,229.

FIG. 7b is an elevational view of the distal end of the probe portion ofthe preferred embodiment of the rotary ophthalmic lens device of thepresent invention.

FIG. 8a is an elevational view of a portion of an alternative embodimentof the rotary ophthalmic lens removal device of the present inventionwherein the probe portion of the device is of a curved configuration,and wherein the protective sheath is positioned in its "operative"position relative to the rotatable lens-reducing head of the device.

FIG. 8b is an elevation view of a portion of an alternative embodimentof the rotary ophthalmic lens removal device of the present inventionwherein the probe portion of the device is of a curved configuration,and wherein the protective sheath is positioned in its "non-operating"position relative to the rotatable lens-reducing head of the device.

FIG. 8c is an enlarged view of segment "C" of FIG. 8a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description and the accompanying drawings areprovided for purposes of describing and illustrating presently preferredembodiments of the invention only, and are not intended to limit thescope of the invention in any way.

It is to be appreciated that the invention described and claimed hereinis a modification of the device which was previously described in Parentapplication Ser. No. 07/984,229. As such, the device described andclaimed in this Continuation-In-Part Application incorporates many ofthe same structural and functional elements as the device previouslydescribed in Parent application Ser. No. 07/984,229.

The following detailed description is intended to focus only on thosestructural and functional elements of the present invention which aredifferent from, or which add to, the elements of the invention alreadydescribed in Parent application Ser. No. 07/984,229now U.S. Pat. No.5,437,678 . Thus, because the entire disclosure of Ser. No. 07/984,229now U.S. Pat. No. 5,437,678 is expressly incorporated herein byreference, the following paragraphs will not endeavor to fullyredescribe each and every structural and functional element which thedevice the present invention shares in common with the device previouslydescribed in Parent application Ser. No. 07/984,229now U.S. Pat. No.5,437,678 . Furthermore, it is to be recognized that the terminologyused herein to refer to components of the invention may differ from theterminology used in the parent application Ser. No. 07/984,229 now U.S.Pat. No. 5,437,678 without necessarily indicating any structural orfunctional difference between the component referred to herein and acorresponding component referred to in the parent application.

FIGS. 1 and 6 of this application contain illustrations of the humaneye. The anatomical structures of the eye, shown in these figures, arelabeled in accordance with the following legend:

Cornea C

Anterior Chamber AC

Iris I

Lens Capsule LC

Lens L

Vitreous Chamber VC

An Ophthalmic Lens Removal System

As shown in FIGS. 1-2, the system 300 of the present invention generallycomprises a handpiece/probe device 302 which is connected to amotor-drive console 304 by way of a rotatable drive cable assembly 306.In the preferred embodiment a proportional or rheostatic control pedal308 is connected to the motor-drive console 304 to facilitatefoot-induced actuation/deactuation, and speed control, of the rotatabledrive cable within the drive cable assembly 306 by the operator. One ormore additional switches or control pedals (not shown) may also beprovided for triggering and controlling the infusion and/or aspirationpumps P₁ and P₂ to facilitate infusion of fluid and/or aspiration offluid and/or debris through the handpiece/probe device 302, as morefully described herebelow.

The handpiece/probe device 302 is preferably configured to include aproximal handpiece portion 310, a distal housing portion 354 and anelongate probe portion 312. As shown in FIG. 1, the elongate portion 312has a distal portion DP which is inserted through the cornea C and intothe lens capsule LC of the eye. The distal portion DP of the probe 312has a distal end DE and a proximal end PE. The cross dimension CD (e.g.,the diameter in the case of a cylindrical probe) of the distal portionDP of probe 312 is preferably no larger at its distal end DE than at itsproximal end PE, as shown in FIG. 2. Such configuration of the distalportion DP serves to facilitate insertion of the distal portion DP intothe eye, in the manner shown in FIG. 1. (drawing is not to scale). Theproximal handpiece portion 310 is sized and configured to be grasped andheld by the human hand. The distal housing portion 354 is smaller indiameter than the proximal handpiece portion 310 (of 302) and extendsfrom of the distal end of the handpiece portion 310 (of 302), as shown.The elongate probe portion 312 is an elongate member which issufficiently small in diameter to be inserted into the mammalian eye,through a small incision or puncture opening.

Sectional showings of the internal components and construction of thedistal housing portion 354 and elongate probe portion 312 are providedin FIGS. 4-4c. With specific reference to FIGS. 4-4d, the distal housingportion 354 is preferably configured to define therewithin a hollowinner chamber 370. A drive member 371 is coupled to the rotatable drivecable within the drive cable assembly 306 and extends into the hollowinner chamber 370, as shown. A rotatable drive shaft 316 is rotatablyconnected or engaged to the drive member 371, such that the shaft 316may be thereby rotatably driven at speeds required for the lensreduction procedure (e.g., 50,000-150,000 rpm). In the embodiment shown,the rotatable drive shaft 316 is inserted into a bore formed in thedistal face of the drive member 371.

A seal (rotating face) 373 is positioned about the outer surface of thedrive member 371, in engagement with the adjacent wall of the hollowinner chamber 370 to prevent seepage or leakage of liquid from thehollow inner chamber 370 into the interior of the proximal hand pieceportion 310 (of 302). In the preferred embodiment, the seal 373comprises a rotating face seal which is mounted about the outer surfaceof the drive member 371, and which incorporates a pliable flange portionwhich seats against and rides upon the adjacent wall or bulkhead 358 ofthe hollow inner chamber 370, thereby forming the desired seal 373 ofthe hollow inner chamber 370.

The elongate probe portion 312 extends in the distal direction from thedistal housing portion 354. As shown, the elongate probe portion 312comprises an axially movable outer sheath 320 which has a hollow bore orlumen 322. A non-rotatable rigid sleeve 350, having a hollow bore orlumen 366, is coaxially centered within the hollow bore or lumen 322 ofthe rigid sleeve 350 and extends longitudinally therethrough. Therotatable drive shaft 316 passes longitudinally through the hollow boreor lumen 366 of the rigid sleeve 350, and is surrounded by a helicalbearing member 364, such as a helical coil of smooth stainless steelwire. Such helical bearing member 364 abuts concurrently against theouter surface of the rotatable drive shaft 316, and the inner luminalsurface of the surrounding rigid sleeve 350. Thus, the helical bearingmember 364 serves to rotatably support the rotatable drive shaft 316 ina coaxially centered position within the hollow bore or lumen 366 of therigid sleeve 350. A transverse bulkhead 358 is formed within the hollowbore or lumen 322 of the axially movable outer sheath 320, near thedistal end thereof. The distal end of the non-rotatable rigid sleeve 350is in abutment with and is supported by bulkhead 358, as shown. Thus,the distal end of the rigid sleeve 350 is maintained in a coaxiallycentered position within the hollow bore or lumen 322 of the axiallymovable outer sheath 320. A central aperture 360 extends longitudinallythrough bulkhead 358, in alignment with the hollow bore or lumen 366 ofthe rigid sleeve 350. The rotatable drive shaft 316 extendslongitudinally beyond the distal end of the rigid sleeve 350, andthrough the central aperture 360 of bulkhead 358, as shown. In theparticular embodiment shown in FIG. 4, 4a and 4b the central aperture360 of the bulkhead 358 is larger than the outer diameter of therotatable drive shaft 316 or otherwise configured to permit infusionfluid to flow from the inner hollow bore or lumen 366 of thenon-rotatable rigid sleeve 350, through central aperture 360, and out ofthe open distal end 324 of the axially movable outer sheath 320. Thus,the bulkhead 358 and its central aperture 360 provide a centeringsupport for the rotatable drive shaft 316 as well as a fluid pathwayparallel to the rotatable drive shaft 316 and a barrier to preventbackflow of fluid into the space of the hollow bore or lumen 322 betweenthe inner surface of the sheath 320 and the outer surface if the sleeve350.

In one alternative embodiment shown specifically in FIG. 4c, the driveshaft 316a is truncated such that its distal end terminates proximal tothe bulkhead 358a. A tubular extension member 420 is mounted on thedistal end of the rotatable drive shaft 316a. Such tubular extensionmember 420 extends through the central aperture 360a formed in bulkhead358a. The central aperture 360a is substantially the same size as theouter surface of the tubular extension member 420, thereby forming asimple sleeve bearing which allows free rotation of the tubularextension member 420. A hollow flow passageway 422 extendslongitudinally through the tubular extension member 420. Inflowapertures 424 are formed in the tubular extension member 420 proximal tothe bulkhead 358a. Such inflow apertures 424 are in fluidiccommunication with the hollow bore or lumen 366 of the rigid sleeve 350.Outflow apertures 426 are formed in the distal portion of the tubularextension member 420, distal to the bulkhead 358a. By such arrangement,a flow of irrigation fluid may be infused through fluid inlet tube 380through hollow inner chamber 370, through the hollow bore or lumen 366of the rigid sleeve 350, through inflow apertures 424, through theinternal hollow flow passageway 422 of tubular extension member 420, andout of outflow apertures 426. Thus, in this embodiment, the bulkhead358a functions dually as a barrier to prevent backflow into the space ofthe hollow bore or lumen 322 between the inner surface of the axiallymovable outer sheath 320 and the outer surface of the rigid sleeve 350and as a centering support for the tubular extension member 420 andthereby for the rotatable drive shaft 316 which permits operativerotation of the tubular extension member 420 within its central aperture360a. A fluid pathway is independently established by the internalhollow flow passageway 422.

In the particular embodiment shown, the axially movable outer sheath 320is longitudinally shiftable, back and forth, relative to thestationarally positioned non-rotatable rigid sleeve 350, bulkhead 358,rotatable drive shaft 316 and distal lens-reducing head 318. This allowsthe axially moveable outer sheath 320 to be volitionally shifted backand forth between an exposed "operative" position wherein thelens-reducing head 318 is sufficiently exposed to perform its intendedlens-reducing function, and a shielded "non-operative" position whereinthe axially movable outer sheath 320 is moved distally to a point wherethe entire lens-reducing head 318 is disposed within the hollow bore orlumen of the axially moveable outer sheath 320. In the embodiment shown,the longitudinal movement of the axially movable outer sheath 320 isfacilitated by anchoring of the axially movable outer sheath 320 to adistal segment 354b of the distal housing portion 354. The distalsegment 354b of distal housing portion 354 is slidably advanceable andretractable over the proximal segment 354a thereof. Spring loadedengagement ball members 357 are seatable in alternate grooves or detents359 to hold the axially movable outer sheath 320 and distal segment 354bof the distal housing portion 354 in either the exposed "operative"position or the shielded "non-operating" position. Accordingly, if it isdesired to move the rotatable drive shaft 316 and distal segment 354b ofthe distal housing portion 354 from the second "operative" position tothe first "non-operative" position, the operator will push or force thedistal segment 354b of the distal housing portion 354 and axiallymoveable outer sheath 320 in the distal direction, causing spring loadedengagement ball members 357 to disengage from the "second" positiongrooves or detents 359a, and to move to a point where the spring loadedengagement ball members 357 will drop into and frictionally engage the"first" position grooves or detents 359b. Thus, the distal segment 354bof the distal housing portion 354 and axially moveable outer sheath 320will be frictionally held and maintained in the first "non-operative"position until such time as the operator volitionally moves the distalsegment 354b of the distal housing portion 354 and axially moveableouter sheath 320 back to their second "operative" position.

Although, as described hereabove, the embodiment shown in the drawingsutilizes an axially moveable outer sheath 320 which is axially moveableback and forth between the first "non-operative" and second "operative"positions, it will be appreciated that, as an alternative, the axiallymoveable outer sheath 320 may be maintained in an axially stationaryposition, and the rotatable drive shaft 316, bulkhead 358 andlens-reducing head 318 may be rendered movable or shiftable, back andforth, to achieve the intended alternate positioning of thelens-reducing head 318 in the first "non-operative" and second"operative" positions relative to the axially moveable outer sheath 320.

MODIFIED DISTAL TIP

In some embodiments of the invention, the axially movable outer sheath320 may also be rotatable about its longitudinal axis so as tofacilitate rotational repositioning of the distal end 324 of the axiallymoveable outer sheath 320 after it has been inserted into the eye,thereby eliminating the need to rotate the entire device. This aspect ofthe invention is particularly useful in combination with the modifiedconfiguration of the distal end 324 of the sheath as described morefully herebelow.

In accordance with the present invention, the distal end 324 of theaxially moveable outer sheath 320 is specifically configured such that,even when the lens-reducing head 318 is deployed in its "operative"location relative to the axially moveable outer sheath 320, a portion(e.g., one side) of the lens-reducing head 318 will remain shielded orprotected by an axial protruding portion (e.g., one side) of the axiallymoveable outer sheath 320. Such modified configuration of the distal end324 of the axially moveable outer sheath 320 serves the dual functionsof a) protecting against inadvertent puncture of or damage to the lenscapsule LC, and b) directing or channeling the forced circulation flowof fluid induced by the lens-reducing head 318 within the lens capsuleLC so as to improve the efficiency of the lens-reduction procedure.

Referring specifically to the embodiment shown in FIGS. 2 and 4-4c, thedistal end 324 of the axially moveable outer sheath 320 is preferablyconfigured such that protruding side 326 of the axially moveable outersheath 320 extends beyond the non-protruding side 328 of the axiallymoveable outer sheath 320. A diagonal or curved transverse surface 330transverses from the distal end of the protruding side 326 to the distalend of the non-protruding side 328. Thus, when the lens-reducing head318 is located in its second "operative" position, as shown in FIG. 4a,the side of the lens-reducing head 318 next to the non-protruding side328 of the distal end 324 of axially moveable outer sheath 320 issufficiently exposed to perform its intended lens-reducing function,while the other side of the lens-reducing head 318 next to theprotruding side 326 of the distal tip 324 of the axially moveable outersheath 320 is protected from contacting adjacent anatomical structures.As such, the protruding side 326 of the distal end 324 of the axiallymoveable outer sheath 320 will prevent or deter that side of thelens-reducing head 318 from inadvertently contacting or perforating theadjacent lens capsule LC (i.e., that portion of the lens capsule LCwhich is next to that side of the axially moveable outer sheath 320).This lateral shielding function of the protruding side 326 of the distalend 324 is particularly advantageous when the axially moveable outersheath 320 is rotated, following its insertion into the lens capsule LC,to an orientation whereby the protruding side 326 of the axiallymoveable outer sheath 320 is next to the closest wall or potion of thelens capsule LC and the non-protruding side 328 is directed toward thecenter of the lens capsule LC.

Although the configuration of the distal end 324 shown in FIGS. 2 and 4is a presently preferred configuration, it will be appreciated thatvarious alternative configurations of the distal end 324, such as thoseshown in FIGS. 5a-5c, may also achieve the intended functions of thisaspect of the invention.

FIG. 5a shows a first alternative configuration for the distal end 324aof the protective axially moveable outer sheath 320a, wherein a straightangle-cut cross sectional transverse surface 330a extends between theprotruding side 326a of the axially moveable outer sheath 320a and thenon-protruding side 328a thereof. Thus, the modified configuration shownin FIG. 5a differs from the preferred configuration shown in FIG. 2 byreplacement of the curved transverse surface 330 (FIG. 2) with asubstantially straight angle-cut transverse surface 330a (FIG. 5a).

Another alternative configuration is shown in FIG. 5b, wherein thedistal end 324b of the axially moveable outer sheath 320b comprises ablunt-tipped closed-ended tube with appropriately positioned inlet andoutlet apertures 391, 392 formed therein, as shown in FIG. 5b. Thelens-reducing head 318, when in its second or "operative" position, isdisposed immediately adjacent the inlet aperture 391 such that theblades of the lens-reducing head 318 will pass or extend partially orfully through the inlet aperture 371 so as to come into contact with,and reduce, any lens L matter which is drawn into or otherwisepositioned within or immediately next to the inlet aperture 371. In thisregard, the rotating lens-reducing head 318 is preferably configured andpositioned to pull or draw fluid (and lens matter) inwardly throughinlet aperture 391. The outlet aperture 392 permits fluid which has beendrawn into the axially moveable outer sheath 320b, and any accompanyinglens debris or fragments, to be expelled out of the hollow bore or lumen322b of the axially moveable outer sheath 320b through the outletaperture 392.

Such configurations of the axially moveable outer sheath 320 as depictedin FIGS. 5b, are conceived to reduce the need for movement of thelens-reducing head 318 between an "operative" and "non-operative"position.

Another alternative configuration of the distal end 324c of the axiallymoveable outer sheath 320c is shown in FIG. 5c. In this alternativeconfiguration, the non-protruding side 328c of the axially moveableouter sheath 320c is cut perpendicular to the longitudinal axis of theaxially moveable outer sheath 320c, and the protruding side 326c isbifurcated or shaped to include multiple axial protrusion, at least oneof which extends slightly beyond the distal most end of thelens-reducing head 318 when the lens-reducing head 318 is disposed inits second or "operative" position as shown.

The manner in which the modified tip portion 324 of the axially moveableouter sheath 320 operates to channel or direct fluid flow within thelens capsule LC, is specifically illustrated in FIGS. 7a and 7b. FIG. 7ashows an embodiment of the device wherein the axially moveable outersheath 320 is cut straight across at its distal end, as described andshown in parent application Ser. No. 07/984,229, now U.S. Pat. No.5,437,678. In such embodiment, the rotation of the lens-reducing head318 causes a flow of fluid to be axially drawn toward the frontal orproximal aspect of the lens-reducing rotating head 318, and theresultant expulsion or exhaust of liquid is deflected radially outwardby the straight-cut distal end of the axially moveable outer sheath 320,in multiple, axially symmetrical lateral directions, as indicated by thearrows shown on FIG. 7a.

FIG. 7b shows a modified device of the present invention wherein theaxially moveable outer sheath 320 incorporates a distal end 324 whereina first or shielded side 326 of the distal end 324 protrudes beyond thelens-reducing rotating head 318, while a second non-shielded side 328 ofthe distal end 324 terminates short of the rotating distal lens-reducinghead 318. In this modified embodiment, the rotating distal lens-reducinghead 318 draws fluid toward the frontal or distal aspect of thelens-reducing rotating head 318. Thereafter, fluid drawn into therotating lens-reducing head 318 is deflected by the axially moveableouter sheath 320 and caused to be expelled or channeled away from thesecond shielded side 328 of the axially moveable outer sheath 320, asshown by arrows on FIG. 7b. In this manner, the modified configurationof the distal end 324 of the axially moveable outer sheath 320 serves tochannel or direct the forced circulation of fluid toward one side (i.e.,the second non-shielded side 328) of the axially moveable outer sheath320. When appropriately positioned within the lens capsule, suchdirected or channeled flow of fluid may be specifically directed aboutthe periphery of the lens capsule so as to optimize and facilitate rapidreduction of the entire lens L, without the need for any significantlongitudinal axial manipulation or movement of the probe.

The ability of the present invention to channel or direct the fluid flowabout the periphery of the lens capsule LC helps to optimize the speedand efficiency with which the ophthalmic lens L is reduced because thecortex or outer portion of the lens L is typically softer and moreeasily reducible than the nucleus or center portion thereof. In thisregard, the channeling or directing of the flow of fluid about theperiphery of the lens capsule LC, results in the soft outer corticalportion of the lens L being preferentially reduced and fluidized by therotation of the lens-reducing head 318. As the outer cortical portion ofthe lens L is reduced the relatively hard central or cataract portion ofthe lens L begins to slowly and gently tumble or rotate within the lenscapsule LC. The continued forced circulatory flow of fluid about theperiphery of the capsule further facilitates such tumbling or rolling ofthe nucleus or cataract portion of the lens L, until reduction of theentire lens L has been accomplished. Thus, in this way, the channelingor directing of the fluid flow within the lens capsule by the modifieddistal end 324 of the axially moveable outer sheath 320 serves tooptimize the speed and efficiency with which the ophthalmic lens L isreduced and removed.

INFUSION/ASPIRATION THROUGH THE PROBE

Additionally, as shown in FIGS. 4-4c, the handpiece/probe device 302 ofthe present invention preferably incorporates separate passageways fora) infusion of irrigation fluid into the interior of the lens capsuleLC, and b) aspiration of fluid/debris from the interior of the lenscapsule LC. Such separate passageways for irrigant infusion andfluid/debris aspiration are shown in FIGS. 4-4b. As shown, the sleeve350 is concentrically positioned around the rotatable drive shaft 316,within the hollow bore or lumen 322 of the protective tubular sheath320. The proximal end 352 of the rigid sleeve 350 is anchored to thedistal housing portion 354a, while the distal end 356 of the rigidsleeve 350 is anchored to a bulkhead 358 positioned within the distalportion of the hollow bore or lumen 322 of the protective axiallymoveable outer sheath 320. A central aperture 360 extends longitudinallythrough bulkhead 358, and the rotatable drive shaft 316, which extendslongitudinally through the hollow bore or lumen 366 of the rigid sleeve350, passes through the central aperture 360 as shown. The helicalbearing member 364 concurrently abuts against the inner surface of thehollow bore or lumen 366 of rigid sleeve 350 and against the outersurface of the rotatable drive shaft 316. Thus, the helical bearingmember 364 serves to hold the rotatable drive shaft 316 in a coaxiallycentered position within the bore 366, while allowing the rotatabledrive shaft 316 to rotate freely. The continuous helical or spiral spacedefined between the individual convolutions of the helical bearingmember 364 forms a helical or spiral flow path through which irrigationfluid may be infused.

The hollow inner chamber 370 formed within the handpiece/probe device302 is in fluidic communication with the irrigation fluid inlet port342, and leads into the proximal end 352 of the bore 366 of the rigidsleeve 350. Seal 373 is configured and constructed to permit rapidrotation of the rotatable drive member 371, while preventing liquid fromescaping from the hollow inner chamber 370 proximally along the drivemember 371 and into other components within the proximal handpieceportion 310 of the handpiece/probe device 302. A pump or pressure sourceP₁, is applied to supply vessel 348 when it is desired to infuse fluidfrom the supply vessel 348, through the elongate probe portion 312.Thus, by actuating pump P₁, fluid may be infused through the irrigationfluid inlet port 342, through hollow inner chamber 370, and through thespiral gap or flow path created between the individual convolutions ofthe helical bearing member 364. As such, the infused fluid will reachthe distal end 356 of the rigid sleeve 350, and will exit throughcentral aperture 360 in bulkhead 358. Such fluid will subsequently passout of the open distal end 324 of the protective axially moveable outersheath 320.

The preferred handpiece/probe device 302 of the present invention alsoincorporates a separate aspiration passageway for aspirating reducedlens matter and/or other fluid or debris from the interior of the lenscapsule LC. In the embodiment shown in FIG. 4, such aspiration pathwaycomprises the peripheral portion of the hollow bore or lumen 322 of theaxially moveable outer sheath 320 which surrounds the outer surface ofrigid sleeve 350. One or a plurality of fluid/debris inlet aperture(s)332 are formed in the sidewall of the axially moveable outer sheath 320near the distal end 324 thereof. In the preferred embodiment shown, theinlet apertures 332 are specifically positioned such that, when theaxially moveable outer sheath 320 is in its second or "operative"position (FIG. 4a) relative to the rotating lens-reducing head 318, suchfluid/debris inlet apertures 332 will be located behind or proximal tothe bulkhead 358, thereby allowing fluid and/or debris to enter into thehollow bore or lumen 322 of axially moveable outer sheath 320 throughinlet apertures 332. A fluid/debris outlet port 344 is formed in therigid cylindrical distal housing portion 354b near the proximal end ofthe elongate probe portion 312 to facilitate the suctioning offluid/debris, through the hollow lumen or bore 322 of the axiallymoveable outer sheath 320, and through aspiration tube 381, intocollection vessel 346. A pump P₂ positioned between fluid debris outletport 344 and collection vessel 346 may be utilized to facilitate suchaspiration of fluid/debris through the probe.

Because the preferred handpiece/probe device 302 of the presentinvention incorporates separate fluid infusion and fluid/debrisaspiration passageways, it is possible to infuse irrigation fluid intothe lens capsule LC while concurrently aspirating lens L debris and/orfluid from the interior of the lens capsule LC. It is to be noted,however, that such concurrent infusion and aspiration are not required.In fact, irrigant fluid may be occasionally or periodically infused, atthe will of the operator, and the fluid/debris may be occasionally orperiodically aspirated, also at will. The infusion and aspirationprocesses may be wholly independent of each other. Furthermore, theindependent processes of irrigation and/or aspiration may be performedsimultaneous with the rotation of the lens-reducing head 318 or whilethe head 318 is in a non-rotating, stationary mode.

Also, it will be appreciated that the infusion and aspiration pathwaysmay be reversed or interchanged by alternately connecting the aspirationtubing and aspiration pump P₂ to inlet port 342 and the infusion tubingand pump P₁ to the fluid/debris outlet port 344.

Although the embodiment shown in the drawings (FIG. 4) incorporates theinlet and outlet ports 342, 344, and their corresponding fluid inlet andoutlet tubes 380, 381, on the distal housing portion 354 of thehandpiece/probe 302, such inlet and outlet ports 342, 344 andcorresponding fluid tubes 380, 381 may be alternately located elsewhereon the device, such as on the proximal end of the handpiece portion 310of the handpiece/probe device 302. For example, the fluid infusion andwithdrawal tubes could be connected to the rear or proximal end of thehandpiece portion 310 of the handpiece/probe device 302, behind theoperators hand, to prevent the tubes from interfering with viewingand/or manipulation of the elongate probe portion 312 by the operator,during use. In such arrangements, a fluid infusion tube or conduit and afluid/debris aspiration tube or conduit will extend through the proximalhandpiece portion 310 of the handpiece/probe device 302 to carry therespective fluid and/or debris through of the hollow inner chamber 370formed within the distal housing portion 354.

POSITIONING AND OPERATING THE PROBE

FIGS. 6a and 6b provide anatomical illustrations of the human eye,showing the preferred method of inserting and positioning the elongateprobe portion 312 so as to minimize the likelihood of damage to the lenscapsule LC, and to maximize the efficiency of the forced fluidcirculation created by the rotating lens-reducing head 318.

As shown in FIG. 6a, the elongate probe portion 312 is preferablyinserted into the lens capsule LC through a previously formed needletract or incision. Such needle tract or incision forms a small firstopening 400 in the cornea C shown at the twelve-o'clock position. Anunderlying second opening 402 is then formed, slightly to the medialside of center, in the anterior aspect of the lens capsule LC. Theelongate probe portion 312 is advanced through the needle tract orincision, and through the corneal opening 400 and capsular opening 402created thereby, such that the distal end 324 is inserted into the lenscapsule LC and such that the distal end of the elongate probe portion312 is angled inwardly toward the mid line of the body, and the proximalportion of the handpiece 310 is angled outwardly, away from the foreheadof the patient. Such preferred angular positioning of thehandpiece/probe 302 is shown in FIGS. 3 and 6a.

As shown in FIGS. 6a and 6b, the axially moveable outer sheath 320 maybe rotated about its longitudinal axis to a preferred rotationalorientation wherein the protruding side 326 of the axially moveableouter sheath 320 is adjacent to the closest wall or portion of the lenscapsule LC and the non-protruding side 328 of the axially moveable outersheath 320 is aimed or directed toward the lens-containing interior ofthe lens capsule LC. By such preferred positioning of the sheath 320,the forced circulation or flow induced by the rotating distallens-reducing head 318, as illustrated in FIG. 7b, will flow around theperiphery of the lens capsule LC to facilitate initial reduction of thecortex of the lens L followed by complete reduction of its nucleus,without the need for any significant axial (i.e., longitudinal) movementor manipulation of the elongate probe portion 312 within the lenscapsule LC. As shown in FIG. 6a, elongate probe portion 312 is insertedinto the lens capsule LC to a depth such that the aspiration inletapertures 332 are located within the lens capsule LC. It is preferred topreferentially bias the location of the aspiration inlet apertures 332toward the non-protruding side 328 of the elongate probe portion 312 inorder to reduce the depth within the lens capsule LC to which theelongate probe portion 312 must be inserted axially such that inletapertures 332 are within the bounds of the lens capsule LC.

After the elongate probe portion 312 has been inserted and the axiallymoveable outer sheath 320 rotated about its longitudinal axis to itsdesired orientation, the axially moveable outer sheath 320 is retractedsuch that the lens-reducing head 318 becomes relocated from its firstshielded or "non-operative" position (FIG. 4b) to its second exposed or"operative" position (FIG. 4a). With the lens-reducing head 318 locatedin its second "operative" position (FIG. 4a), the proportional orrheostatic control pedal 308 is depressed so as to actuate a motorwithin the motor-drive console 304, thereby driving the rotatable driveshaft 316 and the lens-reducing head 318, via rotatable drive cableassembly 306 and drive member 371. In embodiments which incorporate acontrol pedal 308 having proportional or rheostatic capability forcontrolling the rotational speed of the handpiece/probe device 302, theoperator may selectively control the degree to which the control pedal308 is depressed, to adjust the rotational speed of the rotatable driveshaft 316 and lens-reducing head 318.

The ophthalmic lens L is initially in the form of a substantially solidmass, within the interior of the lens capsule LC. The periphery or outercortex portion of the lens L is typically softer than the center ornucleus thereof. Thus, when the elongate probe portion 312 is properlypositioned, the soft outer cortical portion of the lens L ispreferentially reduced and fluidized by rotation of the lens-reducinghead 318. The directed fluid flow created by the device (see FIG. 7b)will preferentially circulate around the periphery of the lens capsuleLC so as to cause the lens L to begin a flat spin within the lenscapsule LC. Such initial spinning of the lens L will cause the softouter periphery of the lens L to be further reduced (e.g., slurried orliquified), thereby decreasing the overall size of the remaining lens Lto a point where it begins to tumble and roll within the lens capsuleLC. As the remaining lens L tumbles, it is repeatedly drawn into contactwith the lens-reducing head 318. As a result, the relatively hardnucleus portion of the lens L will be reduced thereby accomplishingcomplete reduction of the lens L, without the need for any significantaxial (i.e., longitudinal) movement of the elongate probe portion 312within the lens capsule LC.

During or after reduction of the lens L, the aspiration pump P₂ may beutilized to draw lens L fragments and accompanying fluidic debris fromthe interior of the lens capsule LC, into aspiration inlet apertures332, through the aspiration passageway existing within the hollow boreor lumen 322 of the axially moveable outer sheath 320, and out of theaspiration port 344, such that the debris and accompanying fluid may becollected in a fluid/debris collection vessel 346. Simultaneously orseparately clear make up fluid, such as 0.9% NaCl solution, may bepumped, by pump P₁, through fluid inlet tube 380, through fluid inletport 342, through hollow inner chamber 370, through lumen 366, throughcentral aperture 360, and out of the distal end opening of the sheath320, thereby replacing the debris/fluid aspirated from the interior ofthe lens capsule LC with clear make-up liquid. The viscosity and otherfluidic properties of the make-up liquid may be varied to manipulate theforced circulation of fluid induced by rotation of lens-reducing head318 to enhance reduction of the lens L.

After the lens L fragments and debris have been removed and replacedwith clear liquid or other lens L replacement material, the elongateprobe portion 312 may be extracted from the interior of the capsule LCand removed.

Thereafter, the needle tract or incision openings 400, 402 in the corneaand lens capsule respectively through which the elongate probe portion312 was inserted may be closed by appropriate closure means or anappropriate lens L implant introducer may be immediately insertedthrough the same needle tract or incision openings 400, 402, or by wayof a separately formed tract or incision, so as to implant a prostheticreplacement lens L within the interior lens capsule LC. Although thetwelve-o'clock entry position has been described for illustrativepurposes, the above methodologies are not restricted to use of thetwelve-o'clock position, but can be utilized with other entry positionssuch as the nine-o'clock position.

The lens-reducing head 318 is specifically configured and constructed toinclude impeller members 319 which, when rotated, create an axial flowof fluid toward the distal or frontal aspect of the lens-reducing head318, as shown in FIG. 7b. For embodiments having the lens-reducing head318 shown in the figures, the presently preferred rotational speed ofthe lens-reducing head 318 will be 50,000-150,000 rpm. It will beappreciated, however, that the optimal rotational speed of thelens-reducing head 318 will be determined by a number of factors,including the specific size and configuration of the lens-reducing head318 as well as considerations relating to the optimization of theresultant induced forced circulation of fluid which is created by therotation of the drive shaft 316 and lens-reducing head 318 of thedevice. Accordingly, any suitable rotational speed may be employed basedon the specific structural attributes of the device and the physicaleffects created by rotation of the drive shaft 316 and lens-reducinghead 318.

PUMPING/NON-PUMPING EFFECTS OF THE ROTATING ASSEMBLY

In the embodiments shown, the rotation of the drive shaft 316 mayoperate to propel or pump liquid through the helical or spiral flow pathdefined between the individual convolutions of the helical bearingmember 364. In this regard, when the drive shaft 316 is rotated in aclock-wise direction, the rotating outer surface of the drive shaft 316will frictionally propel liquid in the distal direction, through thespiral flow path defined by the convolutions of the helical bearingmember 364. This will result in some pumping or propulsion of liquidthrough the bore 366 of the rigid sleeve 350. This pumping effectcreated by the rotating drive shaft 316 may be utilized as means forenhancing or controlling the infusion of a fluid (e.g., an irrigantsolution) through bore 366 and into the eye. Alternatively, in someembodiments of the invention, it may be desirable to nullify or preventsuch pumping action of the rotating drive shaft 316. One means ofnullifying or preventing such pumping action is to divide the helicalbearing member 364 into a plurality of oppositely wound segments orregions. In this regard, each oppositely wound segment or region of thehelical bearing member 364 will create opposite fluid flow forces withinthe bore 366 as the drive shaft 316 rotates. Such opposite fluid flowforces created by the oppositely wound segments or regions of thebearing member 364 may be intensity-matched to offset or cancel oneanother, thereby resulting in effective cancellation of any fluidpumping effect created by rotation of the drive shaft 316.

It will be appreciated that this aspect of the invention may bepurposely utilized to effect or control pumping or non-pumping of fluidinto the eye during a lens removal procedure using the device of thepresent invention.

CURVED EMBODIMENTS OF THE PROBE

FIGS. 8a-8c show an alternative embodiment of the invention wherein ahandpiece/probe device 302d has an elongate probe portion 312d which isof curved configuration. In this embodiment, the axially moveable outersheath 320d of the elongate probe portion 312d has a distal end 324d ofa configuration substantially the same as that shown in FIG. 2. Theprotruding side 326d of the distal end 324d is laterally opposite thenon-protruding side 328d thereof. The distal housing portion 354d andsheath 320d are alternately shiftable back and forth between a second"operative" position (FIG. 8a) and a first "non-operative" position(FIG. 8b). In this regard, when the distal housing portion 354d andaxially moveable outer sheath 320d are retracted to their fully proximalposition as shown in FIG. 8a, the lens-reducing head 318d of the devicewill protrude out of the open distal end of the sheath, but will remainpartially shielded on one side by the protruding side 326d of the distalend 324d of the axially moveable outer sheath 320d as describedhereabove with respect to the embodiment shown in FIGS. 1-2.Alternatively, when the distal housing portion 354d and axially moveableouter sheath 320d are advanced to their fully distal position, thelens-reducing head 318d will be retracted into the lumen of the axiallymoveable outer sheath 320d, as shown in FIG. 8b.

As shown in FIG. 8c, the curved embodiment of the elongate probe portion312d differs from the above-described preferred embodiment shown inFIGS. 1-4 in that a helical spacing member 490 is disposed between theouter surface of the rigid sleeve 350d and the inner surface of thesurrounding axially moveable outer sheath 320d. This helical spacingmember 490 may be formed of the same material as the helical bearingmember 364d. The helical spacing member 490 is of a cross-sectionaldimension or diameter which maintains the desired coaxial location ofthe rigid sleeve 350d in the surrounding axially moveable outer sheath320d.

As described hereabove, the alternate positioning of the lens-reducinghead 318 in the "operative" and "non-operating" positions may beachieved by either a) axially moving the lens-reducing head 318 relativeto the sheath 320, or b) axially moving the sheath 320 relative to thelens-reducing head 318. In the curved embodiments shown in FIGS. 8a and8b, this is accomplished by axially moving the sheath 320d, back andforth, as shown. It will be appreciated, that in order to accommodatesuch axial movement of the sheath 320, it will be necessary for one ofthe sheath 320 or sleeve 350 to be of rigid curved configuration whilethe other thereof is sufficiently pliable to accommodate such rigidcurved configuration as the sheath 320 is moved back and forth betweenits "operative" position (FIG. 8a) and its "non-operative" position(FIG. 8b). Also, in such curved embodiments, it will be necessary forthe drive shaft 315 to be sufficiently flexible to undergo rotationwhile maintained in the desired curved configuration.

For example, in the device shown in FIGS. 8a and 8b, the outer sheath320d may be formed of material which is flexible or pliable, while therigid sleeve 350d is formed of rigid material, rigidly fixed in thecurved configuration shown. By this arrangement, axial movement of thesheath 320 back and forth between its operative position (FIG. 8a) andits non-operative position (FIG. 8b) may be accomplished while thesheath 320d conforms to accommodate the rigid curved configuration ofthe sleeve 350d. Also, in the embodiment shown, the drive shaft 316 issufficiently flexible to undergo the necessary rotational movement whileheld in the curved configuration shown.

Although the present invention has been described hereabove withspecific reference to a presently preferred configuration andconstruction of the system 300, it will be appreciated that variousmodifications deletions additions and alterations may be made to theabove-described embodiments without departing from the intended spiritand scope of the invention. For example, the modified distal end 324 ofthe protective axially moveable outer sheath 320 may be formed invarious different configurations which still carry out the intendedside-shielding and circulatory flow directing functions describedhereabove.

What is claimed is:
 1. A device which is insertable through the corneaof a mammalian eye and into the lens capsule thereof, for reducing anophthalmic lens within the lens capsule, said device comprising:anelongate probe which is insertable into the lens capsule, said probecomprising:i) an elongate tubular sheath; ii) a rotatable drive shaftextending longitudinally through said elongate tubular sheath, saiddrive shaft having a distal end; iii) a rotatable lens-reducing head onthe distal end of said drive shaft; iv) said tubular sheath having adistal portion, said distal portion being insertable through the corneaand into the lens capsule, said distal portion having a distal end and aproximal end, the distal end of said distal portion being at least aslarge in cross-dimension as the proximal end of said distal portion;and, v) said tubular sheath being further configured and positioned,during operation of the device, such that at least one side of therotating lens-reducing head is shielded by said tubular sheath while theremainder of the rotating lens-reducing head is allowed to contact andreduce lens matter.
 2. The device of claim 1 further in combination witha drive motor which is connectable to said drive shaft, to rotatablydrive said drive shaft and said lens-reducing head.
 3. The device ofclaim 1 wherein said distal portion of said tubular sheath comprises:afirst side which extends beyond the distal end of the rotatablelens-reducing head during operation thereby shielding a first side ofsaid lens-reducing head; a second side which terminates short of thedistal end of the lens-reducing head during operation thereof; and atransverse frontal surface which extends from the distal end of thefirst side of said sheath to the distal end of the second side of saidsheath.
 4. The device of claim 3 wherein said transverse frontal surfaceis curved.
 5. The device of claim 4 wherein said transverse frontalsurface is straight.
 6. The device of claim 3 wherein said distalportion of said sheath comprises:a tube having a closed distal end whichsubstantially surrounds said lens-reducing head during operationthereof, and which has at least one aperture formed near the closeddistal end of said tube to permit said lens-reducing head to contact andreduce lens material through said aperture.
 7. The device of claim 1wherein said rotatable lens-reducing head incorporates an impeller whichis configured to draw a flow of fluid toward said lens-reducing head. 8.The device of claim 7 wherein the distal portion of said tubular sheathis further configured and positioned to shield one side of thelens-reducing head while another side of the lens-reducing head remainsunshielded, and such that most of said flow of fluid is exhausted awayfrom said lens-reducing head in the general direction of the side whichremains unshielded.
 9. The device of claim 1 wherein said deviceincludes means for changing the relative positioning of thelens-reducing head and the tubular sheath between:a non-operatingposition wherein the lens-reducing head is positioned within the tubularsheath; and, an operative position wherein a portion of thelens-reducing head is shielded by a portion of the sheath and theremainder of the lens-reducing head is sufficiently unshielded by thesheath and allowed to contact and reduce lens matter.
 10. The device ofclaim 9 wherein said means for changing the relative positioning of thelens-reducing head and the tubular sheath comprises:apparatus forlongitudinally moving the tubular sheath back and forth while therotatable drive shaft and lens-reducing head remain longitudinallystationary.
 11. The device of claim 9 wherein said means for changingthe relative positioning of the lens-reducing head and the tubularsheath comprises:apparatus for longitudinally moving the rotatable driveshaft and lens reducing head back and forth while the tubular sheathremains longitudinally stationary.
 12. The device of claim 1 whereinsaid tubular sheath is rotatable so as to permit the operator to adjustthe rotational orientation of the tubular sheath, after the device hasbeen inserted into the lens capsule.
 13. The device of claim 1 furthercomprising:a fluid flow passageway extending longitudinally through saidprobe for infusing fluid into the lens capsule.
 14. The device of claim13 wherein said rotatable drive shaft extends through a non-rotatabletubular sleeve having an outer surface and an inner surface, and whereinsaid tubular sleeve is disposed longitudinally within said tubularsheath, and wherein said fluid flow passageway comprises a space whichexists between the inner surface of said tubular sleeve and saidrotatable drive shaft.
 15. The device of claim 14 further comprising:ahelical bearing member having a multiplicity of spaced-apart helicalconvolutions, said bearing member being disposed within the fluid flowpassageway provided between the inner surface of said tubular sleeve andthe outer surface of said rotatable shaft so as to rotatably hold saidshaft in an axially centered position within said sleeve; and, whereby,a helical fluid flow passageway is created by the disposition of saidhelical bearing member within said fluid flow space.
 16. The device ofclaim 15 wherein said helical bearing member is configured such thatrotation of said shaft will pump fluid in the distal direction throughsaid helical fluid flow passageway.
 17. The device of claim 15 whereinsaid helical bearing member is divided into a plurality of oppositelywound segments, said oppositely wound segments to deter any pumpingeffect created by rotation of said drive shaft.
 18. The device of claim14 further comprising a second fluid flow passageway between the outersurface of said sleeve and the inner surface of said tubular sheath. 19.The device of claim 18 wherein at least one fluid/debris inlet apertureis formed in said tubular sheath near the distal end thereof tofacilitate suctioning of fluid and debris through said second fluid flowpassageway.
 20. The device of claim 13 further in combination with:asource of irrigation fluid connected to said fluid flow passageway tofacilitate infusion of irrigation fluid through said fluid passageway.21. The device of claim 15 further comprising:a bulkhead positionedtransversely within the lumen of said tubular sheath, near the distalend thereof; an aperture extending longitudinally through said bulkhead;a tubular extension member interposed between the distal end of saiddrive shaft and said lens-reducing head, said tubular extension memberextending longitudinally through the central aperture of said bulkhead,said tubular extension member being rotatable concurrently with rotationof said drive shaft and said lens-reducing head, said tubular extensionmember having at least one fluid inlet aperture located proximal to saidbulkhead and in communication with said first fluid flow space, and atleast one fluid outlet aperture located distal to said bulkhead; saiddevice being thereby operable such that fluid may be infused in thedistal direction through the first fluid flow space and through thelumen of said tubular extension member, such that said fluid will flowout of the outlet aperture of said tubular extension member and into amammalian eye in which said device is inserted.
 22. The device of claim21 wherein said tubular extension member has an outer bearing surfacewhich rides in contact with said central aperture of said bulkhead assaid tubular extension member rotates in conjunction with said driveshaft and said lens reducing head.
 23. The device of claim 18 further incombination with:a source of negative pressure connected to said secondpassageway to aspirate fluid and debris through said second passageway.24. The device of claim 15 further comprising:a bulkhead positionedtransversely within the tubular sheath, near the distal end thereof; anaperture extending longitudinally through said bulkhead; said tubularsleeve being aligned with said aperture such that said rotatable driveshaft which extends through said tubular sleeve also extends throughsaid aperture, said drive shaft being smaller in diameter than saidaperture such that a space exists to allow fluid infused through saidfluid flow passageway to flow around said drive shaft, through saidaperture, and out of the distal end of the tubular sheath.
 25. Thedevice of claim 24 wherein:the distal end of the tubular sleeve is inabutment with and supported by said bulkhead to hold the distal end ofthe sleeve in position within the surrounding tubular sheath with thelumen of said sleeve in axial alignment with said aperture.
 26. Thedevice of claim 1 further comprising:a fluid flow passageway extendinglongitudinally through said probe for aspirating fluid and debris fromthe lens capsule.
 27. The device of claim 1 wherein said elongate probeis of straight configuration.
 28. The device of claim 1 wherein saidelongate probe is of curved configuration.
 29. The device of claim 1wherein one of said tubular sheath and said rotatable drive shaft arelongitudinally moveable relative to the other to alternately positionthe rotatable lens-reducing head relative to the tubular sheath in:afirst position wherein the lens-reducing head is positioned within thetubular sheath; and, a second position wherein at least a portion of thelens-reducing head is sufficiently exposed to contact and reduce lensmatter during operation of said device.
 30. The device of claim 29wherein a non-rotating tubular sleeve is mounted about said drive shaftand held in fixed or longitudinal relation to said drive shaft andlens-reducing head, said tubular sleeve extending longitudinally withinthe lumen of said tubular sheath.
 31. The device of claim 30 whereinsaid elongate probe is of curved configuration and wherein:saidrotatable drive shaft is sufficiently pliable to rotate while in saidcurved configuration; and, one of said tubular sheath and said tubularsleeve are formed of rigid material shaped in said curved configurationand the other thereof is formed of material which is sufficientlypliable to conform to said curved configuration as the device istransitioned between said first and second positions.
 32. The device ofclaim 31 wherein said tubular sheath is pliable and said tubular sleeveis rigid.
 33. The device of claim 31 wherein said tubular sheath isrigid and tubular sleeve is pliable.
 34. A method for reducing anophthalmic lens within the lens capsule within a mammalian eye, saidmethod comprising the steps of:a) providing a lens-reducing device whichcomprises:i) a tubular sheath having a distal end; ii) an elongate driveshaft extending longitudinally through said tubular sheath and having adistal end; iii) a rotating lens-reducing head positioned on the distalend of said drive shaft; and iv) said sheath being configured andpositioned, during operation of said device, such that the distal end ofthe sheath will shield one side of the lens-reducing head, whileallowing an unshielded portion of the lens-reducing head to remainsufficiently unshielded to contact and reduce lens matter within thelens capsule; b) inserting said device into the eye such that the distalend of the sheath is positioned at a non-centered location within thelens capsule; c) positioning the sheath to cause the shielded side ofthe lens-reducing head to be located adjacent a selected portion of thelens capsule; d) rotationally driving the drive shaft and lens-reducinghead to effect reduction of the ophthalmic lens.
 35. The method of claim34 wherein step b) further comprises:inserting the probe at an anglerelative to a longitudinal axis of the eye, with the distal end of theprobe being located in said non-centered position within the lenscapsule.
 36. The method of claim 34 wherein step c) furthercomprises:positioning said sheath such that the flow of fluid exhaustedfrom the rotating head will be caused to flow around the periphery ofthe lens capsule.
 37. The method of claim 36 wherein the sheath of thedevice is rotatable, and wherein said positioning of said sheathcomprises:rotating said sheath to cause the distal end of the sheath tobecome situated such that the unshielded portion of the sheath isdirected toward the center of the lens capsule.
 38. The method of claim34 wherein step c) comprises:rotating said sheath such that the flow offluid created by rotation of the lens-reducing head will:i) initiallyspin the lens in a flat plane within the lens capsule to facilitateinitial reduction of a peripheral portion of the lens; and ii)thereafter cause the remainder of the lens to tumble within the lenscapsule to cause repeated contact of the lens with the lens-reducinghead, thereby facilitating complete reduction of the remaining portionof the lens.
 39. The method of claim 34 further comprising the stepof:infusing a fluid into the lens capsule.
 40. The method of claim 34further comprising the step of:aspirating fluid and debris from the lenscapsule.
 41. The method of claim 34 further comprising the stepof:concomitantly infusing fluid into the lens capsule and aspiratingfluid and debris from the lens capsule.
 42. The method of claim 34wherein:the device provided in step a) incorporates means foralternately positioning the lens-reducing head, relative to the sheath,in:i) a first position whereby the entire lens-reducing head is locatedwithin and shielded by the sheath; and ii) a second position wherein oneside of the lens-reducing head is shielded by the distal tip portion ofthe sheath and a remaining portion of the lens-reducing head isunshielded and capable of contacting and reducing lens matter within thelens capsule; and wherein the method further comprises the stepsof:initially causing the lens-reducing head to be located in said firstposition during insertion of the probe into the lens capsule; andsubsequently causing the lens-reducing head to become positioned in saidsecond position to facilitate reduction of the ophthalmic lens withinthe lens capsule.
 43. The method of claim 42 wherein, prior to insertionof the device in step b, of the method, said method comprises theadditional step of:causing said lens-reducing head to be in said firstposition relative to said sheath to facilitate insertion of the deviceinto the eye; and, prior to the performance of step d, said methodcomprises the additional step of: causing said lens-reducing head to bemoved to said second position, relative to said sheath, to facilitatereduction of the ophthalmic lens.
 44. The method of claim 43 wherein thestep of "causing the lens-reducing head to be placed in said firstposition relative to the sheath" is accomplished by longitudinallyadvancing the sheath in the distal direction.
 45. The method of claim 43wherein the step of "causing the lens-reducing head to be located insaid second position relative to said sheath" is accomplished bylongitudinally retracting said sheath in the proximal direction.
 46. Arotary ophthalmic lens-reducing device for in situ reduction of theophthalmic lens of a mammalian eye, said device comprising:a handpieceportion which is sized and configured to be grasped by the human hand;and an elongate probe portion which extends distally from said handpieceportion, said probe portion comprising:i) an elongate tubular sheathhaving a distal end; ii) a rotatable drive shaft extendinglongitudinally through said elongate tubular sheath, said drive shafthaving a distal end and an outer surface; iii) a rotatable lens-reducinghead member positioned on the distal end of said drive shaft; saidtubular sheath having a distal end portion which is configured such thata first side of said distal end portion is longer than an oppositesecond side of said distal end portion; said tubular sheath beingalternately moveable back and forth between:i) a first position whereinboth the first and second sides of the distal end portion of the sheathextend beyond the distal end of the rotatable lens-reducing head,thereby shielding the entire lens-reducing head; and ii) a secondposition wherein only the first side of said tubular sheath extendsbeyond the distal end of the rotatable lens-reducing head, therebyallowing the portion of the head which is next to the second side of thesheath to be sufficiently unshielded to contact and reduce lens matter.47. The device of claim 46 wherein said lens-reducing head comprises atleast one impeller member to draw an axial flow of fluid in the proximaldirection, toward the distal end of the lens-reducing head.
 48. Thedevice of claim 47 wherein the configuration of the distal end portionof the sheath, causes at least some of the fluid which is exhausted bythe lens-reducing head to flow toward said second side of said sheath.49. The device of claim 46 wherein said tubular sheath is rotatable soas to permit the operator to adjust the rotational positioning of thetubular sheath, after the device has been inserted into the lenscapsule.
 50. The device of claim 46 further comprising:a first fluidflow passageway extending longitudinally through said probe for infusingfluid into the lens capsule.
 51. The device of claim 50 wherein saiddrive shaft has an outer surface and is surrounded by a tubular sleevehaving a lumenal surface, and wherein said tubular sleeve is disposedwithin the lumen of the tubular sheath and about the outer surface ofsaid drive shaft such that said first fluid flow passageway is providedbetween the lumenal surface of said tubular sleeve and the outer surfaceof said rotatable drive shaft.
 52. The device of claim 51 furthercomprising:a helical bearing member having a multiplicity ofspaced-apart helical convolutions, said bearing member being disposedwithin the first fluid flow passageway formed between said tubularsleeve and the outer surface of said rotatable shaft so as to rotatablyhold said shaft in an axially centered position within said sleeve; and,a helical fluid flow path is thereby created by the disposition of saidhelical bearing member within said first fluid flow passageway.
 53. Thedevice of claim 51 wherein a second fluid flow passageway is definedbetween the outer surface of said sleeve and the inner surface of saidtubular sheath.
 54. The device of claim 53 wherein at least onefluid/debris inlet aperture is formed in said tubular sheath near thedistal end thereof to facilitate suctioning of fluid and debris throughsaid second passageway.
 55. The device of claim 51 further comprising:abulkhead positioned transversely within the lumen of the tubular sheath,near the distal end thereof; an aperture extending longitudinallythrough said bulkhead; the lumen of said tubular sleeve being alignedwith said aperture such that said rotatable drive shaft extends throughsaid aperture, said drive shaft being smaller in diameter than saidaperture such that a space exists around said drive shaft to allow fluidinfused through said first fluid passageway to flow around said driveshaft, through said aperture, and out of the distal end of the tubularsheath.
 56. The device of claim 55 wherein:an annular shoulder is formedin the proximal surface of the bulkhead; and, wherein the distal end ofthe tubular sleeve is in abutment with said annular shoulder such thatthe distal end of said tubular sleeve is thereby supported in aco-axially centered position within the surrounding tubular sheath. 57.The device of claim 51 further comprising:a bulkhead positionedtransversely within the lumen of the tubular sheath, near the distal endthereof; an aperture extending longitudinally through said bulkhead; atubular extension member interposed between the distal end of said driveshaft and said lens-reducing head, said tubular extension memberextending longitudinally through the aperture of said bulkhead, saidtubular extension member being rotatable concurrently with rotation ofsaid drive shaft and said lens reducing head, said tubular extensionmember having at least one fluid inlet aperture located proximal to saidbulkhead and in communication with said first fluid flow passageway, andat least one fluid outlet aperture located distal to said bulkhead; saiddevice being thereby operable such that fluid may be infused in thedistal direction through the first fluid flow passageway and through thelumen of said tubular extension member, such that said fluid will flowout of the outlet aperture of said tubular extension member and into amammalian eye in which said device is inserted.
 58. The device of claim57 wherein said tubular extension member has an outer bearing surfacewhich rides in contact with said central aperture of said bulkhead assaid tubular extension member rotates in conjunction with said driveshaft and said lens-reducing head.
 59. The device of claim 52 whereinsaid helical bearing member is configured such that rotation of thedrive shaft within such helical bearing member will operate to pumpfluid in the distal direction, through the helical fluid flow pathcreated by the disposition of said helical bearing within said secondfluid flow passageway.
 60. The device of claim 52 wherein said helicalbearing member comprises a plurality of opposite wound segments to deterany pumping effect from being created by rotation of said drive shaft.61. The device of claim 50 further in combination with:a source ofpressurized irrigation fluid connected to said fluid flow passageway tofacilitate infusion of irrigant fluid through said fluid passageway. 62.The device of claim 46 further comprising:a second fluid flow passagewayextending longitudinally through said probe for aspirating fluid anddebris from the lens capsule.
 63. The device of claim 62 further incombination with:a source of negative pressure connected to said secondpassageway to aspirate fluid and debris through said second passageway.64. The device of claim 46 wherein said elongate probe portion of saiddevice is of straight configuration.
 65. The device of claim 46 whereinthe elongate probe portion of a device is of said curved configurationand said drive shaft is sufficiently pliable to rotate while in saidcurved configuration.
 66. The device of claim 65 wherein said driveshaft extends through a tubular sleeve, said tubular sleeve beingpositioned longitudinally within the tubular sheath, and wherein one ofsaid tubular sleeve and said tubular sheath is pliable while the otherthereof is rigid and disposed in said curved configuration such that thepliable one thereof will conform to the curved configuration of therigid one thereof, as the tubular sheath is moved back and forth betweensaid first and second positions.
 67. The device of claim 66 wherein saidtubular sleeve is rigid and said tubular sheath is pliable.
 68. Thedevice of claim 66 wherein said tubular sleeve is pliable and saidtubular sheath is rigid.